A DMZ or demilitarized zone is a line dividing two opposing military forces. In this officially neutral area, the warring factions are not allowed to maintain troops or installations, and they are prohibited from conducting any military operations.
The most famous present-day DMZ is the one dividing North Korea and South Korea, roughly along the 38th Parallel. Korea's DMZ was established by the UN in 1953, when the Korean War Armistice was negotiated. During the Vietnam War, there was a DMZ between North and South Vietnam, as well.
Other current DMZs in Asia include the Kuwaiti/Iraqi border, and the UN-controlled zone between the Golan Heights (held by Israel) and the rest of Syria.
"The DMZ on the Korean Peninsula is an accidental wildlife reserve, since few people enter it. Tigers may even roam the 3-mile wide and 155-mile long region."